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Question: Answered & Verified by Expert
An EM wave from air enters a medium. The electric fields are E1=E01x^cos2πvzc-t  in air and E2=E02x^cosk2z-ctin medium, where the wave number k and frequency v refer to their values in the air. The medium is non-magnetic. If ϵr1 and ϵr2 refer to relative permittivities of air and medium respectively, which of the following options, is correct?
PhysicsElectromagnetic WavesJEE MainJEE Main 2018 (08 Apr)
Options:
  • A ϵr1ϵr2 =12
  • B ϵr1ϵr2 =4
  • C ϵr1ϵr2 =2
  • D ϵr1ϵr2 =14
Solution:
2834 Upvotes Verified Answer
The correct answer is: ϵr1ϵr2 =14
airmed=cc/2=2=μ0ϵ0μr2ϵr2μ0ϵ0μr1ϵr1 

ϵr1ϵr2=14

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